It is known that the technique of particle charging prior to fabric filtration results in a pressure drop reduction as particle charging prior to fabric filtration produces a charged particle bed on the filter surface which is more open and less densely packed than when non-charged particles are collected. It is also known that SO.sub.2 may be removed from flue gases by certain sorbents such as sodium bicarbonate and Nahcolite.
Examples of prior art are: PA1 Schuff ----4,290,786; PA1 Schuff ----4,220,478; PA1 Johnstone ----2,924,294; PA1 Calvert ----4,169,714.